Method of blasting



No. 232,640. V

I It F. L. HALLOOK. Method of Blasting.

Patented Sept. 28,1880.

UNITED STATES PATENT @FFICE ROBERT F. L. HALLOGK, OF VALLICETO, CALIFORNIA.

METHOD OF BLASTING.

SPECIFICATION forming part of Letters Patent No. 232,640, dated September 28, 1880.

Application filed February 7, 1880.

To all whom it may concern Be it known that I, ROBERT F. L. HAL- LOOK, of Valliceto, Oalaveras county, in the State of California, have invented an Improved Method of Blasting; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing.

My improved method of blasting is especially valuable in mines where nitro-glycerine or other quick-acting explosive is used; but it can also be used in all kinds of land or surface blasting.

Maillefert discovered that by placing a cartridge or charge of powder upon the bed or bottom of a river, lake, or bay, so that the weight of water above it would serve as a tamping, he could produce very satisfactory results in blasting. By a very simple adaptation I employ this process for blasting in mines and on land, and thereby I gain several important advantages over the ordinary method of blasting, especially where a quick-actin g explosive is used.

My methodof blasting consists in placing the cartridge or charge of powder or other explosive directly upon the surface to be blasted without preparing a drill-holl or other cavity to receive it. I then place a column or body of water over the cartridge or charge and fire the blast. The resistance of the superposed Water to the escape of the gases causes a greater portion of the energy of the blast o be exerted downward against the surface on which it is placed, so that the rock is shattered and broken and reducedto a much better condition for removal than rock blasted by the ordinary method, and in mining the rock or ore will be reduced to a better condition for milling or other treatment.

The plan which I have adopted, and which I consider preferable on account of its extreme simplicity and cheapness, is as follows ltake a piece of muslin or other piece of cheap fabric and make it into a bag. The larger this bag is made the better will be the result obtained; but for all practical purposes a bag as large as an ordinary flour-bag is all that is necessary for effective work. This bag I then immerse in coal-tar or other waterproofing substance or compound, after which I squeeze off all surplus tar or compound, leaving the bag practically water-tight. fill with water. I then place the cartridge on the face of the rock, or on the spot to be disrupted or broken up, insert the fuse and cap, and then place the bag of water over the cartridge. I then lute or close up all cracks in the rock or ground leading from the place where the cartridge rests, so as to make the ground around the charge practically air-tigh t. I then fire the charge. The result will be, first, the rock or other surface on which the charge rests will be broken and disrupted by the force of the explosion; and, second, the bag of water will be bursted, and the water will instantly be discharged over the gases and fumes generated by the explosion, so that they are completely allayed and condensed, and no inconvenience will result to the workmen by disagreeable or unhealthy fumes. This latter result is of greatimportancein mines,especially where nitroglycerine compounds or dynamite is used for blasting. The fumes of these powders are not only disagreeable and unhealthy, but actu' ally poisonous to some systems, so that several minutes of time are lost after each blast before the workmen can venture near the place of discharge when the charge is exploded in the ordinary way; but by my method no time is lost, as the fumes are completely allayed by the deluge of water that the explosion produces, and work can be resumed immediately. By this means I avoid the trouble and expense of drilling holes to receive the charges, which is one of the greatest expenses and annoyances connected wit-h blasting, and it enables me to keep hoisting ore all the time, as I can fire one blast after another as fastas required, and thus keep a plentiful supply of ore all the time.

I use about one-third more powder than re quired by the old process to produce the same quantity of ore; but the extra cost of the powder is but a small item compared with the numerous advantages and benefits derived from the method.

,I do not confine myself to any particular This bag I then vessel or form of vessel for providing and aptially such as described, upon the explosive plying a column of water over the charge; but agent.

What I do claim, and desire to secure by In witness whereof I have hereunto set my 10 Letters Patent, ishand and seal.

5 The method of blasting which consists of ROBERT F. L. HALLOCK. [L- s] placing the explosive agent directly on the sur- Witnesses: face of the rock or land and superposing wa- W. F. CLARK,

ter confined in a suitable receptacle, substan- E. K. WOOD. 

